Pulverizer



June 29, 1937, I 1 A*R KUHLENGEL 42,085,261

PULVER I Z ER Filed July 14. 1954 s sheets-sheet 1 3 Sheeis-Sheet 3 PULVERIZER L. R. KUHLENGEL Filed July 14. 1954 June 29, 1937.

Patented `inne 29, 1937 UNITED STATES 4PATENT OFFICE PULVERIZER Application July 14, 1934, Serial No. 735,147

6 Claims.

This invention relates generally to pulverizers and more particularly to feeding means therefor.

In operating grinders to pulverize to a nely ground state clay, coal, lime, mica, cinnamon and other material, it is desirable to interpose closure means between the feed hopper and the grinding chamber in order to prevent the finely ground material from backing up or escaping from the feeding chamber into the feed hopper.

The main objects of this invention are to provide a feeding means which operates between the feed hopper and the grinding chamber and includes a feed trough having a gate or closure plate adjacent to the grinding chamber and which is normally closed and is opened to permit the discharge of material into said grinding chamber when a sufficient amount of material has accumulated in the feed trough.

, Other objects of the invention are to provide a feeding mechanism vincluding a feed trough, the discharge end of which is provided with a closure member, said discharge end being provided with an upwardly turned lip which serves to arrest the material in the trough until a sufficient amount has accumulated therein, whereupon the accumulated material is discharged from said trough into the grinding chamber of the grinder, thereby opening said plate to effect the discharge of material.

Further objects of the invention are to construct the feed trough and the feed hopper in a single casting whereby said feed trough'can be readily attached to and detached from the grinding machine without the necessity of dismantling the latter, and to provide a removable plate in said grinding machine to permit ready access to the closure plate of said feed trough for the purpose of observation or to serve as a clean-out.

4With these and other objects in view, my invention consists in certain novel features of construction and arrangement of parts, hereinafter more fully described and claimed and illustrated in the accompanying drawings, in which- Figure 1 is a longitudinal vertical cross section of a grinding machine equipped with my improved feeding means.

Figure 2 is a vertical transverse cross section taken on line 2 2 of Figure l.

Figure 3 is a vertical cross section taken on line 3 3 of Figure l. v

Figure 4 is a vertical cross section taken on line d-l of Figure l.

Figure 5 is a reduced top plan View of the feed hopper and feed trough casting.

Figure 6 is .a longitudinal cross section taken on line 6-6 of Figure 5.

Figure 7 is a rear end elevational view of same.

Referring by numerals to the accompanying drawings, I0 indicates a grinder, II the feed hopper, and I2 the feeding means by means of which the material to be pulverized is fed from the hopper to the pulverizer. In the instant case, the pulverizer is shown as being of the hammermill type including a, casing I4 having a grinding chamber I5, a revoluble shaft IE journaled in said casing,` and a plurality of hammers I1 pivotally mounted on spacer disks I8 which latter are fixed on said shaft within said grinding chamber.

Casing I4 is provided with a cover i9 hinged at 2D. This cover forms an opening 2I in which is received the forward or discharge end 22 of a horizontally disposed trough 24. The latter is preferably formed as a. single piece casting with hopper II, as shown in Figures 5 to '7, and the lower end of said hopper opens into said trough. One or more troughs may be used and where a plurality of troughs is used theyv are arranged side by side as in the instant case. where three troughs are used.

The rear or outer end 25 of each trough extends past the lower end of the hopper and terminates in a lateral flange 2E, the upper portion of which is merged with the rear inclined wall oi the hopper as indicated at 26a. The forward or discharge ends 22 of the trough extend a suitable distance past the front wall of the hopper and enter opening 2I formed in grinder IU.

Where a plurality of troughs is used they are separated from each other by a longitudinally disposed partition wall 2l which is formed integral with the casting. The forward or discharge end of the trough casting has formed integral therewith a. transverse wall 28 which extends upwardly a suitable distance above the bottoms of the troughs, The inner side of this Wall is inclined upwardly and forwardly, as indicated at 28a. The outer side is disposed vertically at its lower portion, as indicated at 28h, while the upper portion is inclined upwardly and rearwardly, as indicated at 28e. The angle of inclination of portion 28e is the same as that of closure plates 29 which close the discharge ends of the troughs. Preferably a separate closure plate 29 is provided for each trough so that they can operate independently of each other. Each plate is pivotally mounted at its upper end by means of a pin 30. Preferably a single pin is used for all of the plates and the ends of said pin are secured to the side walls 3| of the trough casting. Each'plate is held in closed position against the respective end of the feed trough by gravity. Thus the communication between the grinding chamber and the troughs and the hopper is normally closed and the dust and finely ground material contained in the grinding chamber cannot enter-the hopper.

The raised wall or lip 28 in each trough serves to retain the material therein until suflicient amount has accumulated, whereupon said material is forced from the trough, thereby temporarily displacing the closure plate. As soon as the material has been discharged from the hopper, the respective closure plate by virtue of gravity assumes its normal closed position.

The material is fed forwardly in each trough by means of a screw conveyor 32 operating therein. This conveyor is mounted on a horizontally disposed shaft 34 which is journaled in a bearing 35 fitting into the rear end of -the trough casting and formed integral with a gear housing 36. The

latter is bolted tofiange 26 of the trough and hopper casting and its outer open end is closed by a plate 31 detachably secured thereto in any suitable manner.

The shafts 34 are interengaged by means of intermeshing gears 38 which are fixed on said shafts within said housing. In the 'present instance, the intermediate shaft termina-tes within said housing, as indicated at 34a in Figure 1, while the two outer shafts have their ends journaled in bearings 39 formed in plate 31. One of the outer vshafts has fixed thereon a large beveled gear 4U and meshing with this is a small beveled pinion 4I which is fixed to a shaft 42. This shaft is journaled in a bearing 43 and extends from said housing at right angles to conveyor shafts 34 and is driven in any suitable manner.

Cover I9 is provided with an elongated opening 44 and the top wall of the trough extension is provided with a similarly shaped opening 45. When the hopper and trough casting is in place on the grinder, these openings coincide and are adapted to receive a box-shaped cover 46 which is secured in position on cover I9 by bolts 4l and extends inwardly into engagement with opening 45. When it is desired to observe the action of the respective closure plates 29, said cover 46 can be removed. The grinder is provided with the usual cage 48 through which the ground material is discharged from the grinding chamber.

As stated before, hopper I I and .feed trough 24 are formed integral with each other in a single casting. This casting-is secured to the grinder by bolts 49 which engage flanges 50 of casing lli and are screw-seated in a pad I formed integral with the underside of the forward end of trough casting 24. Additional supports for the casting are provided by means of studs 52. The upper end of hopper I I is anged and can have secured thereto a. material feed duct (not shown).

In the operation of the machine, the material to be ground is deposited into the hopper II and is discharged therefrom into the respective feed troughs 24. The screw conveyors 32 operate in said troughs and move the material toward the forward end where it accumulates against the lip or transverse wall 28 and against the closure plate 29. Due to said lip and to the weight of the closure plate a certain amount of material has to accumulate in each trough before the closure plate thereof opens to permit the discharge of the material into the grinding chamber I5. As soon as this discharge takes place the closure plate by virtue of gravity assumes its normal closed position. Thus it will be noted that the closure plate is moved into open position at denite intervals and only upon the discharge of the material from the feed trough into the grinding chamber. At all other times the closure plate closes the communication between the grinding chamber and the feed troughs and the hopper.

'Ihus the dust laden air contained in the grinding chamber cannot escape by way of Athe feed troughs and the 4hopper and the discharge oi' material into the grinding chamber is not interfered with. The hopper and the troughs vbeing formed integral in .a single casting facilitate assembly thereof and attachment to the grinder and the mounting of the feed mechanism in said casting. The hopper .and trough casting can be removed from its position on the grinder simply by removing bolts 49 and the cover 46 without the necessity of dismantling the grinder or any part thereof.

Preferably each closure plate 29 isprovided with a weight 29a or other means for urging said closure plate into closed position.

The material can be conveyed to the hopper II by a suitable conduit attached to said hopper 49 as indicated in dotted lines in Figure 1. The lip 28 prevents continuous discharge of material from the trough and the subsequent continuous open position of the closure plate and the latter is opened only at regular intervals when the periodical discharge of material takes place.

By making the feed hopper and the feed troughs in a single piece casting' and by forming the casing of the grinder in such a manner that this casting can be readily applied thereto, the cost of assembling is reduced to minimum and the grinder is rendered inoperative only for a short length of time.

While I have shown and described herein the preferred form of my device, it is obvious that various changes in the construction thereof can be made without departing from the spirit of my invention.

I claim:

1. In a grinder, the combination with a grinder casing having a grinding chamber. of a feed trough having its discharge end extending through an opening in said casing into said grinding chamber, an upwardly projecting lip transversely formed in the discharge endof said feed trough to cause accumulation of material therein, the inner side of said lip being inclined upwardly and outwardly, and a closure plate pivotally mounted at its upper end above said discharge end and extending downwardly against saidv lip for closing said discharge end ofv said feed trough, said closure plate being movable into open position upon the discharge of material accumulated in the discharge end of said feed trough.

2. In a grinder of the class described, the combination of a casing having a grinding chamber and an open-ended extension, a feed trough having its forward end extending into said extension and opening into said chamber, a transverse lip formed on the bottom of said forward end of said trough and projecting upwardly a suitable distance to cause accumulation oi material in said end and to cause the discharge of said material at spaced intervals, and a closure plate pivotally mounted on said forward end and overlapping said lip and closing said end to prevent communication between said grinding chamber and said trough, said closure plate being displaceable from its closed position by the material discharged from said trough into said chamber.

3. In a grinder, the combination of a casing having a grinding chamber and an open-ended extension, a feed hopper, a feed trough having its rear end communicating with said hopper and having its forward end extending into said extension and opening into said chamber, an upwardly projecting lip formed on the bottom of the forward end of said trough to cause the discharge of material therefrom at spaced intervals, a screw conveyor in said trough for feeding the material toward said forward end thereof, and a closure plate mounted on said forward end of said feed trough and normally held in engagement therewith and overlapping said lip to close the communication between said chamber and said feed trough, said closure plate being displaceable by the material upon the discharge thereof from said trough. I

4. In a grinder, the combination of a grinder casing having an open-ended extension, a feed trough having one end extending into said extension and opening into said casing, means for conveying material through said feed trough, an upwardly projecting lip formed on the bottom of the inner end of said trough to cause the discharge of material into said casing at spaced intervals, and a closure plate pivotally mounted on the forward end of said feed trough forwardly of and above said lip for closing said end and preventing communication between said trough and said chamber, said plate being displaceable into open position by the material discharged from said feed trough into said casing.

5. In a grinder, the combination with a casing having a grinding chamber and an open-ended extension, of a unitary structure comprising a feed hopper and a feed trough, said feed trough extending into said extension and having its discharge end opening into said grinding chamber, a transverse lip formed on the bottom of said discharge end of said trough to retard the discharge of material therefrom, said lip having its inner face inclined forwardly and upwardly, means for removably securing said structure in position on said casing, a closure plate pivotally mounted on the forward end of said trough and overlapping said lip, thereby closing said feed trough and preventing dust from escaping from said grinding chamber into said trough, said closure plate being movable into ope'n position by the material discharged from said trough, there being formed in the juxtaposed walls of said extension and said t'rough coinciding openings to provide access to said discharge end, and removable means for closing said openings.

6. In a grinder, the combination with a casing having a grinding chamber and an open-ended extension, of a feed trough removably secured to said extension and having its discharge end opening into said chamber, afeed hopper arranged above the other end of said trough and opening thereinto, a material conveying means in said trough for forcing the material toward the discharge end thereof, an upwardly and outwardly inclined lip formed transversely on the bottom of said discharge end to cause discharge of material at spaced intervals, a closure plate movably mounted on said discharge end and yieldably closing the same, the lower end of said plate overlapping said lip, whereby dust is prevented from escaping from said grinding chamber, said plate being displaceable by the material discharged from said trough.

LOUIS R. KUHLENGEL. 

